Low layer paging indicator processing system and method for multi-layer communication equipment used in a wireless communication system

ABSTRACT

A wireless communication system implements wireless communications between a base station and a plurality of User Equipments (UEs) including paging of UEs by initially processing paging indicator information. A first embodiment involves a UE&#39;s physical layer L1 being configured for interpreting a paging indicator (PI) to activate a preset decoding configuration to process paging data in a pre-specified paging channel (PCH). A second embodiment involves the physical layer control of a next higher level, L2, interpreting the paging indicator and configuring the physical layer L1 to process paging data in a pre-specified PCH.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/349,433 filed Feb. 7, 2006, which is a continuation of U.S.application Ser. No. 11/144,871 filed Jun. 3, 2005 which is acontinuation of U.S. application Ser. No. 10/400,878, filed Mar. 27,2003 which claims the benefit of U.S. Provisional Application No.60/368,786, filed Mar. 29, 2002, which are all incorporated herein byreference as if fully set forth.

FIELD OF INVENTION

This invention relates to improving the efficiency of paging processingin communication equipment used in a wireless communication systemhaving multiple layers of processing such as a system designed inaccordance with the present Third Generation Partnership Project (3GPP)specifications.

BACKGROUND

The popularity of wireless telecommunication has given rise to therecognition of physical limitations on available bandwidth anduniformity concerns. Accordingly, a need for standardization haspermeated the telecommunications industry. In January 1998, the EuropeanTelecommunications Standard Institute—Special Mobile Group (ETSI SMG)agreed on a radio access scheme for Third Generation Radio Systemscalled Universal Mobile Telecommunications Systems (UMTS). To furtherimplement the UMTS standard, the Third Generation Partnership Project(3GPP) was formed in December 1998. 3GPP continues to work on a commonthird generational mobile radio standard.

A typical UMTS system architecture in accordance with current 3GPPspecifications is depicted in FIG. 1. The UMTS network architectureincludes a Core Network (CN) interconnected with a UMTS TerrestrialRadio Access Network (UTRAN) via an interface known as Iu which isdefined in detail in the current publicly available 3GPP specificationdocuments.

The UTRAN is configured to provide wireless telecommunication servicesto users through User Equipments (UEs) via a radio interface known asUu. The UTRAN has base stations, known as Node Bs in 3GPP, whichcollectively provide for the geographic coverage for wirelesscommunications with UEs. In the UTRAN, groups of one or more Node Bs areconnected to a Radio Network Controller (RNC) via an interface known asIub in 3GPP. The UTRAN may have several groups of Node Bs connected todifferent RNCs, two are shown in the example depicted in FIG. 1. Wheremore than one RNC is provided in a UTRAN, inter-RNC communication isperformed via an Iur interface.

Fundamental to 3GPP and the architecture of other relativelysophisticated systems is the adoption of a multi-layer structure such asthe Open Systems International (OSI) seven layer model which wasdeveloped by the International Organization of Standardization (ISO).

The OSI model which is implemented through 3GPP systems has a physicallayer in respective stations, base stations and user equipment, whichactually transmits and receives the wireless telecommunication signals.The physical layer is commonly referred to as Layer 1 or L1. Otherstandard layers include a data link layer, Layer 2 (L2); a networklayer, Layer 3 (L3); a transport layer, Layer 4 (L4); a session layer,Layer 5 (L5); a presentation layer, Layer 6 (L6); and an applicationlayer, Layer 7 (L7). Through the layered hierarchy, communicationinformation and data is conveyed over various predefined channels wherethe information is formatted and distributed through the functioning ofthe higher layers and then passed to the physical layer for actualtransmission. The layered structure and associated channel definitionsand data format structures as defined by 3GPP Technical Specificationsprovide for a highly sophisticated and relatively efficient datacommunication system.

One function implemented in 3GPP systems is paging. Under current 3GPPTechnical Specification such as TS25.221 and TS25.331 V3.1.2.0, thepaging function is implemented utilizing two different data signalsnamely, a Page Indication (PI) and substantive paging data. Inaccordance with current 3GPP specification, a PI is sent on a pageindication channel (PICH) in advance of the substantive page data. Thatdata is sent on a separate paging channel (PCH) which is transported bya Secondary Common Control Physical Channel (SCCPCH).

Since base stations are transmitting information for many UEs, anindividual UE only needs to process that portion of the informationbeing broadcast from the base stations that relates to that particularUE. In order to process paging data, a UE monitors a PICH until itreceives an appropriate PI designated for that UE. After the appropriatePI signal is received by the UE, that UE then knows that substantivepaging data is being sent for it on an associated PCH via an SCCPCH.Otherwise, the UE need not process paging data on the SCCPCH, such aspaging data intended for a different UE.

To avoid the need for unnecessary processing of data intended for otherUEs, a UE's physical layer, L1, is selectively instructed by the UE'shigher layers as to which signals to process and the manner in which thesignals are to be processed in accordance with the format of thosesignals. Much of the direct control of the physical layer is conductedby the data link layer, Layer 2, which in turn receives instructions andinformation from the network layer, Layer 3, which typically includes aradio resource control (RRC). The RRC provides information to the L1control processing elements in Layer 2 to instruct the physical layer,L1, to process data received on specific channels such as a predefinedSCCPCH.

In 3GPP systems, each SCCPCH has a specific format for transporting datawhich, as noted above, can include data for a paging channel (PCH). Abase station may broadcast more than one paging channel with the use ofmultiple PICHs and PCHs. However, current 3GPP specifications dictatethat only one PCH may be carried by a SCCPCH and that a unique PICH isdefined for each PCH. Where multiple PICHs are being broadcast, the UEsmake a determination as to which PICH it can monitor for a PI signalusing a known algorithm as set forth in TS25.304 V3.11.0 Section 8.

Once the selection of which paging channel the UE should monitor ismade, the RRC in level 3 directs the L1 control to instruct the physicallayer to process signals received on the appropriate PICH. At that time,because there is a one-to-one correspondence with the PICHs and thePCHs, it is known which PCH and accordingly which SCCPCH is associatedwith the PICH which the physical layer has been instructed to monitor.Once the UE receives an appropriate PI over the PICH which it ismonitoring, the physical layer L1 of the UE must be instructed toprocess the data on the SCCPCH which is carrying the associated PCH inorder to process the associated paging data.

As shown in FIG. 2, conventional implementations have the PICH processedat the physical layer L1, but the decision to receive PCH is made byhigher layers, typically within the RRC. Therefore, the processed pagingindicator data is sent by L1 processing to the L1 Controller of L2 thenon to the RRC in L3 which signals L1 processing via L1 Control of L2 toreceive and process the PCH data if the paging indicator is positive. L1Control is the Layer 2/3 interface to Layer 1.

For illustrative and comparative purposes, FIG. 2 shows a fairly typicalexample where there is a two frame gap between a PI and thecorresponding paging data. The size of the gap is known in the radiolink and transport channel (RL/TR) configuration for PCH reception.

As shown in FIG. 2, conventionally the physical layer L1 conducts chipprocessing of the received (RX) signal for each frame as it is receivedand then processes the received frames in accordance with the manner ithas been configured by the L1 Controller of Layer 2. Thus, the physicallayer L1 decodes the PI received on the PICH it is monitoring by the endof the received frame, Frame #1, in which the PI is contained. Implicitin FIG. 2, is that the physical layer L1 has been preconfigured by theL1 Controller to monitor the particular PICH based on instructionsreceived from the RRC.

When decoded, the PI is sent by L1 to the physical layer Controlprocessing unit of L2 which in turn requests new instructions from theRRC of L3 based on the decoded PI. The RRC then responds to the controlprocessor of L2 instructing it to configure the physical layer L1 toprocess paging data from a specific PCH. The L2 processor in turnconfigures the physical layer for PCH to process paging data received onthe specified PCH. This instruction process typically spans in timeabout one and one half frames, i.e. completely over Frame #2 whichfollows the frame in which the PI was received and into the next frame,Frame #3. The paging data is sent in the next frame, Frame #4, at whichtime the physical layer L1 has already been configured to receive thepaging data in the selected PCH and follows those configurationinstructions to process the paging data during Frame #5, i.e. after theconclusion of receipt/chip processing of the paging data in Frame #4.

The present inventors have recognized that the configuration of thephysical layer L1 to process the paging data indicated by a PI can beperformed more efficiently.

SUMMARY

The present invention comprises two different embodiments for processingof paging indicator information. The first embodiment involves thephysical layer L1 being configured for interpreting the paging indicatorPI to activate a preset decoding configuration to process paging data ina pre-specified PCH. The second embodiment involves the physical layercontrol of L2 interpreting the paging indicator and configuring thephysical layer L1 to process paging data in a pre-specified PCH.

Generally, a wireless communication system implements wirelesscommunications between a base station and a plurality of User Equipments(UEs) including paging of UEs. Preferably, the UEs are constructed witha multi-layer processing system having a configurable lowest physicallayer L1 which receives wireless communication signals and selectivelyprocesses the received signals according to its then presentconfiguration. Preferably, the UEs have a first higher level L2 thatincludes a physical layer processing control for reconfiguring thephysical layer L1, and a second higher layer L3 that includes a radioresource control (RRC) for providing the L2 physical layer processingcontrol with paging channel parameters.

As in the prior art, a paging indicator (PI) is received by a UE inadvance of corresponding paging data and the UE is configured to processthe paging data after receiving the PI.

The invention provides a UE with a low level buffer for storingpredetermined paging data processing configuration data. The UE's firsthigher level L2 is associated with the UE's RRC such that, when aspecific PI that is determined by the UE's RRC is identified to the UE'sfirst higher level L2, the UE's physical layer L1 is configured tomonitor for the specific PI. In conjunction with this, correspondingpaging data processing configuration data is stored in the buffer. TheUE's physical layer L1 is associated with the UE's L2 physical layerprocessing control such that, when the UE's physical layer L1 identifiesthat the specific PI has been received, the UE's physical layer L1 isthereafter configured to process paging data based on the paging dataprocessing configuration data stored in the buffer without communicationwith the RRC or other components of higher layers, i.e. higher than L2.

Preferably the UE lower layer buffer is a physical layer buffer withinthe UE's physical layer L1 for storing predetermined paging dataprocessing configuration data. The UE's physical layer L1 is thenassociated with the UE's L2 physical layer processing control such that,when the UE's physical layer L1 is configured to monitor for receptionof a specific PI that is determined by the UE's RRC, correspondingpaging data processing configuration data is stored in said physicallayer buffer. At that time the UE's physical layer L1 is also configuredto access the buffer and use the stored data to reconfigure itself uponreceiving and processing the specific PI. For a 3GPP system, thephysical layer L1 is configured to monitor a specific page indicationchannel (PICH) when it is configured to monitor for the specific PI andthe physical layer L1 is configured to monitor a specific separatepaging channel (PCH) which is transported by a Secondary Common ControlPhysical Channel (SCCPCH) when it is configured to process thecorresponding paging data.

Alternatively, the UE lower layer buffer is a physical layer processingcontrol buffer within the UE's first higher level L2 for storingpredetermined paging data processing configuration data. The UE's firsthigher level L2 is then associated with the UE's RRC such that, when aspecific PI that is determined by the UE's RRC is identified to the UE'sfirst higher level L2, corresponding paging data processingconfiguration data is stored in said physical layer processing controlbuffer. The UE's physical layer L1 is then associated with the UE's L2physical layer processing control such that, when the UE's physicallayer L1 identifies to the UE's first higher level L2 that the specificPI has been received, the UE's physical layer L1 is configured toprocess corresponding paging data by the UE's L2 processing controlbased on the paging data processing configuration data stored in thephysical layer processing control buffer. Where the UE is for a 3GPPsystem, the physical layer L1 is configured to monitor a specific pageindication channel (PICH) when it is configured to monitor for thespecific PI and the physical layer L1 is configured to monitor aspecific separate paging channel (PCH) which is transported by aSecondary Common Control Physical Channel (SCCPCH) when it is configuredto process the corresponding paging data.

Other objects and advantages of the present invention will be apparentto those skilled in the art from the following detailed description andthe drawings.

BRIEF DESCRIPTION OF THE DRAWING(S)

FIG. 1 is a schematic diagram of a typical UMTS system in accordancewith current 3GPP specifications.

FIG. 2 is a timing diagram of a prior art scheme for paging indicatorprocessing.

FIG. 3 a is a timing diagram of a first embodiment for paging indicatorprocessing in accordance with the present invention.

FIG. 3 b is a representative illustration of a processing layerhierarchy for a UE configured to implement the first embodiment of thepresent invention.

FIG. 4 a is a timing diagram of a second embodiment for paging indicatorprocessing in accordance with the present invention.

FIG. 4 b is a representative illustration of a processing layerhierarchy for a UE configured to implement the second embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A User Equipment (UE) is provided for use in a wireless communicationsystem, such as illustrated in FIG. 1, which implements wirelesscommunications between a base station and a plurality of UEs includingpaging of UEs. The UEs are constructed with a multi-layer processingsystem, preferably a seven layer system as depicted in FIGS. 3 b and 4b. A configurable lowest physical layer L1 receives wirelesscommunication signals and selectively processes the received signalsaccording to its then present configuration. Preferably, a first higherlevel, L2, includes a physical layer processing control forreconfiguring the physical layer L1, and a second higher layer, L3,includes a radio resource control (RRC) for providing the L2 physicallayer processing control with paging channel parameters.

Preferably, the system initiates paging by a base station transmitting apaging indicator (PI) on a page indication channel (PICH) in advance ofthe substantive page data in accordance with current 3GPPspecifications. Current 3GPP specifications specify that the page datais sent on a separate paging channel (PCH) which is transported by aSecondary Common Control Physical Channel (SCCPCH) with a 2, 4 or 8frame gap from the transmission of the PI. The PI is received by the UEin advance of corresponding paging data and the UE is configured toprocess the paging data after receiving the PI.

A first embodiment of the invention is to provide a User Equipment (UE)with a system for paging indicator (PI) and related paging dataprocessing where the UE's physical layer L1 processing interprets thepaging indicator as illustrated in FIGS. 3 a and b. To implement this,the UE's physical layer L1 includes a buffer in which the radio link andtransport channel (RL/TR) configuration for PCH reception is stored whenthe physical layer L1 is configured to monitor a corresponding PICH forreceipt of a specified PI. The pre-configuration of the physical layerL1 to monitor a particular PICH for receipt of a specified PI includesinstructions to the physical layer to automatically reconfigure itselfin accordance with the data stored in the buffer when the specified PIis received and decoded. This embodiment reduces unnecessary interlayersignaling since the required configuration information is available toL1 processing based on system information previously processed by higherlayers at the time it is configured to monitor for a specified PI.Accordingly, the invention reduces unnecessary power consumption sincehigher layer processors can remain in a powered down state while L1processes the PI to determine if there is a need for the UE to receivethe PCH in a given DRX cycle. Conservation of power is significant for aUE since many UEs are battery powered and battery life can beconsiderably shortened by frequently powering processing components forhigher layers.

As with the conventional system shown in FIG. 2, in the embodiment ofthe invention shown in FIGS. 3 a and b, the physical layer L1 conductschip processing of the received (RX) signal for each frame as it isreceived and then processes the received frames in accordance with themanner it has been configured by the L1 Controller of Layer 2. Thus, thephysical layer L1 decodes the PI received on the PICH it is monitoringby the end of the received frame, Frame #1, in which the PI iscontained. Implicit in FIG. 2, is that the physical layer L1 has beenpreconfigured by the L1 Controller to monitor the particular PICH basedon instructions received from the RRC. However, unlike the conventionalsystem, the UE is configured such that the PCH processing configurationis stored in a physical layer L1 buffer for use when the specified PI isdecoded by the physical layer. Accordingly, when decoded, the PItriggers the physical layer L1 to automatically assume the configurationrequired for processing the corresponding paging data which is to bereceived on the corresponding PCH, instead of the PI being sent by L1 tothe physical layer Control processing unit of L2 which in turn wouldrequest new instructions from the RRC of L3.

In addition to eliminating excessive interlayer signaling, the inventionmakes it possible to advance the transmission and receipt of thecorresponding paging data. As with the prior art, a UE embodying thepresent invention can receive a PI in Frame #1 and be ready forreception of the corresponding paging data in the PCH in Frame #4 forprocessing in Frame #5. However, the present invention also enables theUE to receive a PI in Frame #1 and be ready for reception of thecorresponding paging data in the PCH in Frame #3 for processing in Frame#4. Accordingly, if current 3GPP specifications are amended to permit aone frame gap between the PI and the paging data such a faster pagingprocess can be accommodated without modifying the UE but merelyproviding the appropriate data to the buffer to process the PCH and pagedata in an earlier frame time period.

A second embodiment of the invention is to provide a User Equipment (UE)with a system for paging indicator (PI) and related paging dataprocessing where the UE's physical layer L1 Controller of L2 interpretsthe paging indicator as illustrated in FIGS. 4 a and b. To implementthis, the UE's physical layer L1 Controller has an associated L2 bufferin which the radio link and transport channel (RL/TR) configuration forPCH reception is stored when the L1 Controller is instructed toconfigure the physical layer L1 to monitor a corresponding PICH forreceipt of a specified PI. Preferably, the UE is configured with a RadioResource Controller (RRC) in level 3 that provides the parameters andother information to the Controller of L2.

When the RRC instructs the L1 Controller of L2 to configure the physicallayer L1 to monitor a particular PICH for receipt of a specified PI, theL2 buffer receives the parameters necessary to instruct to the physicallayer L1 how to be configured to receive the corresponding page datawhich will be received on the corresponding PCH after receipt of thespecified PI. Accordingly, when the physical layer L1 decodes the PI,the PI is sent the L1 Controller of L2 which then uses the data storedin the L2 buffer to directly instruct the physical layer L1 how to beconfigured for processing the corresponding paging data which is to bereceived on the corresponding PCH without requesting furtherinstructions from the RRC of L3.

This embodiment also reduces unnecessary interlayer signaling since therequired configuration information is available to L1 Controller of L2based on system information previously processed by higher layers at thetime it receives the parameters needed to configure the physical layerL1 to monitor for a specified PI. In particular signaling to and fromthe RRC is reduced.

While both embodiments are viable, the first embodiment is faster thanthe second embodiment. However, there is some logic and bufferingrequired in the first embodiment that would normally be done above theL1 processing layer when time permits. There is benefit in processingtime, reduced signaling and reduced power consumption if L1 processingperformed in the first embodiment interprets the paging indicator andmakes the decision for reception of the PCH channel data. Similarbenefits, except no reduction in power consumption, would be realizedfor the second embodiment.

It should also be understood that the present invention can be fullyimplemented as a software module. In such a case, the module is easilyadaptable to changes desired by the system administrator. For example,certain easy functions described hereinbefore as being implemented in L1processing may be implemented by L1 control and vice versa.

1. A user equipment (UE) comprising: a hierarchy of processing layersincluding a configurable lowest physical layer (L1) and a next lowestlevel (L2); the L1 having a first configuration configured to receiveand decode a paging indicator (PI) in a given PI channel (PICH); the L2having a buffer and a controller configured to control L1; the L1 in thefirst configuration configured to send a decoded PI that identifies apaging channel PCH in which a page for the UE will be transmitted to theL2; and the L2 configured to reconfigure the L1 into a secondconfiguration, in response to receiving a decoded PI from the L1, basedon instructions stored in the L2 buffer such that in the secondconfiguration the L1 is configured to process paging data to be receivedon the PCH identified by the decoded PI.
 2. The UE of claim 1 whereinthe L1 is configured to reconfigure itself to operate at a frame gapresponsive to a received frame gap value.
 3. The UE claim 1 wherein thesecond L1configuration is a configuration in which the L1 is configuredto receive paging data over a Secondary Common Control Physical Channel(SCCPCH).
 4. The UE claim 1 wherein: the hierarchy of processing layersincludes a higher level (L3); the L3 having a radio resource control(RRC) that is configured to provide instructions to the L2 controller;and the L2 is configured to store configuration instructions in the L2buffer for controlling the configuration of the L1 based on instructionsreceived from the RRC of L3.
 5. The UE of claim 4 wherein the L1 isconfigured to reconfigure itself to operate at a frame gap responsive toa received frame gap value.
 6. The UE claim 4 wherein the second L1configuration is a configuration in which the L1 is configured toreceive paging data over a Secondary Common Control Physical Channel(SCCPCH).
 7. A method for a user equipment (UE) comprising: providing ahierarchy of processing layers including a configurable lowest physicallayer (L1) and a next lowest level (L2) having a buffer; receiving anddecoding a paging indicator (PI) in a given PI channel (PICH) by the L1in a first configuration; sending a decoded PI, that identifies a pagingchannel PCH in which a page for the UE will be transmitted, to the L2 bythe L1 in the first configuration; and controlling the reconfigurationof the L1, based on instructions stored in the L2 buffer, into a secondconfiguration by the L2 in response to receiving a decoded PI from theL1 such that in the second configuration the L1 is configured to processpaging data to be received on the PCH identified by the decoded PI. 8.The method of claim 7 wherein the hierarchy of processing layers isprovided with a higher level (L3) having a radio resource control (RRC),further comprising: providing instructions to the L2 controller by theRRC; and storing configuration instructions in the L2 buffer forcontrolling the configuration of the L1 by the L2 based on instructionsreceived from the RRC.
 9. The method claim 7 further comprising the L1reconfiguring itself to operate at a frame gap responsive to a receivedframe gap value.
 10. The method claim 7 wherein the reconfiguring the L1from the first configuration to the second configuration configures theL1 to receive the paging data over a Secondary Common Control PhysicalChannel (SCCPCH).